Seasonal storage of hydrogen in porous rocks: decarbonising heating in the UK

For the first time, this project will investigate a novel technology for the storage of pressurised hydrogen gas, to provide energy on a seasonal timescale. This will contribute to the decarbonisation of the UK’s energy supply and to energy security. You will be trained in the interpretation of seismic data, and the integration of borehole and other subsurface data with exposed surface analogues to produce models for the subsurface geology of storage sites in the Midland Valley of Scotland. You will produce a technical, and an economic, assessment of the viability of the technology.

Background:
Efforts to decarbonise the UK’s energy supply have so far concentrated on the production of electricity, for example through low-carbon sources such as wind power and solar photo-voltaics. However, the largest share of energy usage is in so-called ‘space heating’, i.e. the heating of homes and work places. Currently the vast majority of this heat is provided from natural gas combustion via central heating boilers. It is not practical to capture CO2 emissions from millions of individual boilers, so it has been proposed to switch the UK’s gas network from being based on natural gas (predominantly methane) to hydrogen, which produces only water upon combustion. The demand for space heating in the UK fluctuates by a factor of 3 to 4 between winter and summer. Hydrogen production from ‘spare’ renewable energy (e.g. from wind or solar power) in the summer could be stored for use in winter. Equally, if hydrogen is produced from fossil fuel feedstocks (and the resulting CO2 sent for geological storage) then it may be more efficient to produce decarbonised hydrogen at a constant rate throughout the year, and store the summer surplus for winter use.

Proposed Research:
While the large scale storage of hydrogen has been considered in an offshore setting within the UK (Amid et al., 2016), onshore store is expected to be much cheaper and closer to potential users. There are several depleted oil and gas fields in the Central Belt of Scotland, which are potentially attractive sites for the underground storage of hydrogen. A regional appraisal will be undertaken of a selected region of central Scotland to identify a catalogue of potential subsurface storage sites, close to facilities of hydrogen generation potential. Subsurface techniques to be used are derived from hydrocarbon exploration and CO2 storage. Candidate sites will be geologically evaluated using methods our group has established for CO2 storage. This includes an understanding of reservoir thickness, 3D geometry, porosity, permeability and seals on the top, base and sides. Volumes (hence tonnages) of stored hydrogen will be calculated and risked for uncertainty. Risks of hydrogen leakage will be assessed by geological setting and by fundamental calculations of hydrogen mobility within porous rock media. This project will combine existing subsurface data (seismic, borehole) with studies of the reservoir and seal units that are exposed locally, to build geological models of each of the candidate sites. These will be modelled using state-of-the-art digital modelling software, to estimate the technical feasibility of engineered hydrogen storage onshore. Reservoir flow modelling will examine the ranges of possibility for injection rates, retention security ,and commercially viable rates of production during recovery. A high-level techno-economic assessment will be made, with guidance from the Industrial CASE partner (TBA), of the engineering facilities required to generate, transport, inject and recover hydrogen. Outline calculations will also establish engineering losses during the round trip generation, injection and recovery, which combined with geological losses by reaction and diffusion, will enable calculations of efficiency. Outline cost estimates will be prepared of the borehole and surface compression and pipe developments, to enable comparison with established business options.

Applicants are invited from UK/EU citizens who should have, or expect to gain, a 2:1 BSc or MSc in the GeoSciences, Physical Sciences, or Mathematical Sciences. You are not expected to arrive with all the skills

Download the full research proposal from http://www.ed.ac.uk/geosciences/postgraduate/phd/programmes-supervisors/physical-sciences/phd-projects/